1. Field of the Invention
The present invention relates to a portable wireless apparatus that includes an antenna and performs communication with other apparatuses.
2. Description of the Related Art
Recent portable wireless terminals such as cellular phones have a built-in antenna provided in an end portion of a casing.
In a folding-type portable wireless terminal, when an antenna is in a lower casing which has operation keys, it is preferable that the antenna be accommodated in an end portion located opposite a hinge.
For example, when a user uses a portable terminal apparatus, such as a folding-type portable wireless terminal, to make a call, the user opens up the folding-type portable wireless terminal so that the user can originate a call and places the portable wireless terminal against the user's ear to use the portable wireless terminal. In such a case, the entire end portion where an antenna is contained is generally rarely covered with a hand or face, causing no damage to the radio characteristics of the antenna. When the antenna is disposed in the end portion of the casing, there is an advantage that the radio reception state changes negligibly depending on the state of the portable wireless terminal (whether it is opened or closed).
At present, portable wireless terminals are becoming smaller and thinner. Therefore, with the foregoing structure in which the antenna is contained in the end portion of the lower casing where the operation keys are disposed, the built-in antenna and a microphone for communicating a voice are disposed close to each other.
When the microphone, which includes a conductive material, is placed near the antenna, the microphone may affect the antenna's transmission and reception sensitivity.
The microphone outputs noise when being used. The noise may affect the antenna's transmission and reception sensitivity.
In order to overcome this problem, it has been proposed to dispose the built-in antenna near the hinge mechanism so that the antenna can be away from the microphone. However, in the case where the built-in antenna is disposed near the hinge, when the user uses the portable terminal apparatus to make a call, the user opens up the folding-type portable wireless terminal so that the portable wireless terminal can originate a call and places the portable wireless terminal against the face to use the portable wireless terminal. As a result, a portion containing the antenna is covered with a hand and the face, which may result in degradation of the antenna's transmission and reception sensitivity.
It has been proposed to provide a plurality of built-in antennas in a casing of a portable wireless terminal so that a different antenna can be used to make a call. However, when the built-in antennas are provided in the casing to avoid the effect of a microphone that is disposed nearby, the size of the portable wireless terminal increases.
Thus, there has been a demand for a portable wireless apparatus that can avoid degradation of transmission and reception sensitivity of an antenna without involving an increase in the size of a casing.